Tungsten-furnace.



A. APPELBERG.

TUNGSTEN FURNACB.

APPLICATION FILED 00T. m. 1nos.

1,006,620. Patented 0ct.24,1911.

FqL

3 SHEETS-SHBET'I.

lnx/entier Axel Appelbzrq,

A. APPELBERG.

TUNGSTEN FURNACE.

APPLICATION FILED 00116, 190s.

1,006,620. V Patented 0013.24, 1911.

- 2 3 SHEBTS*SHEET 2t VWinesses: Inventor k -s 7 Axel Appesberq,

I I by Agt?) A APPELBBRG.

TUNGSTEN FURNACE.

APPLICATION FILED 00116. 1908.

Patented 0st. 24, 191i 3 SHEETS-SHEET 3.

lnvemor MUY on soHENneirnn-Y,

oonnnnr, n Gone-L TICE OF NEWT YORK.

BEST AvAnABLECOH- @Flll-lll@ 35E-vll YORK, il-LSSIGNOR T0 ELECTRIC Specification. nf .Letters Estant.

Patented @ein 234i, llL

Applicton i'ile ctober "i6, 1903. Serial No. 457,982,

oepufble ol? effecting desired chemical changes in materiel under treatment. l. pre'licr 'to .ineke the metal chamber l. of cest gunuuetel ovide it with tubular extemsons l busses mm'nu'md through one tungsten tube und then ucl-oss through vthe Copper' block und up the other tubeAs l ui, muy conce-rn: 5 und i pr no flown that l, .AXEL "ierumi:no u und 5 huving rubber closures 6 und 7 Whieh t ot the King of Sweden, residing` ut l oanrbe remove lit desired. Digi-nllgg.; 'county o' Schenectady, State i The metal chamber l. is nclosed in a metal ww Yorkl have invented eerteinnew l jacket S tlu'ouglr which water may be ein' useful Improvements in Tungsten-Fun .:ulated to eool'the chamber.. xNithin 'the 6G ha of uhich the following is t speciinurnetul-clnnuber l, two 'tubular tungsten heutl 9 und 'lO-ure arranged with their tops n inventhni relates to electric furfu l nelosed respectively in tungsten bushings und elnboflie n1 apparatus in which nieuw; ll undv l?. clamped in copper terminal blocks und. vonipou man he heated und treated et 13 'und le* to which electrical connection is .65

uguiu'oziehing the vapor-initie" l established by unter cooled brasstubes 15 "been und without. the dunner e ind 16 passing through the cover 2 of the l:foutumuuuing the xneteriuls under 1r r- 1 turnuee und insulated therefrom. as shown meut with carbon, oxygen, orA other foreign l in detail. jfig. Ll. Each .of these .brass elements. l tubes is shaped like :t U und each forms one 70 My improved. furnace .is of theresishiuue 'ieriuinul of the furnace. The enf-tight joint type und is provided with u resistance con between `thecurrent Supply tube l5 und the ilu/etui Consisting of substantiallypureinelul Cover sl'iofwix in detail in Fig. 4;, em' operative ut un exceedingly .high teuuifnn-V bodies u. l,crew tln'ended sleeve '17 .soldered und Jiurthcrium'e, the furnace is pra tu lube tif und provided with e Clamping 75 vided with :ill udjuncts necessary or con-l uut l'tl insulated vtroni the top of the furnace' veulent to ready use on un industrial soule or by u. paper washer l). An annule-r ring 20, 1:3 1l IHCHVHSIOJS llbOlzttOly lHVStlgittlOlls :lli l also of pul'u'y: iggulltgg th@ Sleeve 17 fron" high @reperiti/uros under oonditioi'ls4 hitherto he furnace top uud'rests on e' ince Washer vuutttunoble. filiere hereinafter described l il separating two loud oollurs Z2 und 23. 8O

uu."Y :ree einbodyingu resistance cun- Lhe tungsten tubes und 10 are et their duetzr of 'tun/feiten, :incl ll. consider that t' lower ends hehl respectively in the tungstenl nietil is typ .nl of the generul clues o" bushings 2l und 25 @lumped in e copper base trut/ery inetuls which muy be used to i block consisting of a, central casting ,'26 buvthe furnace hereinafter ing suxniqjaliuch-ical segments-27 und28 bolt# 85 l ed. thereto, these segments being supported. rlhe deteils'o one embodiment of hay in by u pluto 522)* having' olinenings therein i linz tion ere illustrated in the drawings forni with the eyliiulricul openings olf the 'tung-- eert olf lhs specification, in Which-- l sten heaters and also in line with the tubn ure 'l is un elevation partly-.iu sect-io@ 1 hub extensions l und 5 of the metal ohztnl- 90 lf i) is another section teken et ii `ber l.' i i Y este l; Figfl 'is :1. plan; untlllig About euch tubular tungsten heutefus en e, mil ol? the insulated joint through u nich i ruugnwl u, heut reflecting screen consisting of ourrcntis introduced to the resistance 'nieuw l :in outer tungsten tube 30, an inner tungsten A lun-Q o the fum-toe w. tube 3l, und u packing of alumina, or other" 9.5l n; fui-nece comprises en :mir-tight metal 'l inert powder bctweengthe tubes. A tungsten elunube il fitted 'with e cover 2' through bushingl nin-y be used to support the inner which extends e inetul tube '.3 whereby the tubo Ell. on the lower inturned edge of the olmuiber muy be connected with u vacuum l outer tube 30. The entire: screen issupp-ort- ,nuup end nutybe oxluuisted und maintained eu on three have buttonsSB resting on the 100 in in exhausted condition throughout the lcopper buse block and serving is electrical operi lou of furiiutee; or Wherebz7 the i insulators. This buse block maintains eleomuy .urst be exhzulsted and then l lricnl couumtiou between the lower ends of lilled `with. hydrogen or other inert with the tungstt'n heutes, so that current enter"- rif-speclz to the 'tungsten of the heater but ing through one of the brass tubes l5 or 16 105 Y l adjustable bolt 89 that a definite and pre- It so happens that tungsten and some of the other exceedingly refractory metals, when made up in large tubes such as are here disclosed, undergo a sort of progressivel shrinkage or gradual decrease in length during normal use, particularly during the learly part of their life. To avoid any inconvenience from this cause, the present furnace is provided With spring actuated means for maintaining a tight contact between the tungsten tubes and their respective terminals. To this end, a Water cooled brass tube 3st of the complexA yoke shape shown in Fig. l' passes through the copper base block 26 and .has bot-h ends extending upward through the cover 2, from which they are respectively insulated by rubber sleeves and 36. A spiral spring 37 is secured to the upper ends of these tubes by a clamp 38 and is so supported. from an determined pull can be exerted on the brass tube 34 and thereby made available to insure firm pressure and good contact between the tungsten tubes and their upper and lower co per blocks or terminals. I consider this feature as of very considerable importance, for it entirely eliminates arcing at the ends of the tungsten tubes. The tungsten tubes above described, may be made by carrying out the process described in the paragraph beginning with line 79, page l of my U. S. Patent #953574, issued April 5,

1910. After lthe tubes become seasoned by heating to a temperature higher than 1300o C. as described in the above mentioned patent, the furnace can operated at temperatures much higher "than 13000 C. and in fact, approaching' the melting point of tungsten, which is something above 3000O C. I prefer to use alternating current for the furnace and for 9 inch tungsten tubes with an internal diameter of 2 inches and a thickness of one-eighth of an inch, I may use 5000 ampcres or even-more.

It will be readily understood that-a furnace of this type can be calibrated as to temperature, and that thereafter, anyl particui lar condition of temperature and gas pressure can be duplicated With certainty merely by regulating the current supply, the degree of exhaustion, etc.

This furnace can be used for a great variety of technical and scientific Work, such for instance as the reduction of oxids by hydrogen at high temperatures, the production of alloys of the more refractory metals, such as tungsten, molybdenum, titanium, thorium, uranium, etc., the vaporization of refractory oXids, such as magnesia, and the fusion of other oxids such as alumina or calcium oxid, all in Aan atmosphere free from carbon. The furnace has proved very serviceable for the production and treatment of tungsten and molybdenum filaments either a suitable cri fiblf framework of tungsten, can be introduced incasso continuous heat treatment of such met-als Without dai'iger'of contaminating the charge by vapors or by charged particles given olf by the heating elements. The entire absence of carbon anywhere 'Within the furnace permits the attainment of the highest temperatures Without danger of producing a carbid.

When the furnace is being run as a vacuum furnace for the treatment of metal filaments, I prefer to suspend those laments from brass tubes 40 and 41 passing through cover 2 and separated therefrom by rubber sleeves -1-2 and 48. Each of these brass tubes is provided with a glass window ist in line with the hot zone `of the furnace,

thus enabling the operator to Watch. the

utilize a saddle comprising a-tungsten bar 47 suspended bv a tungsten or molybdenuml Wire 48. After the filaments haveA been given the desired heat treatment in a vacuum, air or lglydrogen may be admitted to the furnacfe and then onremoval of the tubes 40 `and il vwith their inclosing rubber sleeveis lf2 and 43, the filaments may be 'liftelout'through the cover 2 Withput detach ng that cover from the furnace chamber This isA a great convenience\vvhen ilan ents are being treated on-a commercial seal i In case the furnace is being run as a hydrogen furnace, I prefer to keep it filled with hydrogen at atmospheric pressure and to introduce the filament or Whatever is being treated through the tubular extensions 4 and 5 at the bottom of the furnace, the rubber blocks 6 and 7 being removed to permit this. The lightness of the hydrogen y revents it from escaping at the bottom o the furnace, and the furnace charge, carried in or suspended over a and Withdrawn from the hot zone of the furnace Without contaminating the inert atmospbere of that Zone and Without the inconvenience of cooling down the'furnace after each run or of unbolting the cover or otherwise partially dismantling the furnace.

If a circulation of hydrogen through the hot Zones appears desirable, it may be 0btained by admitting streams of hydrogen through the tubes 40 and 41 at the top of the furnace and allowing that hydrogen to escape through the extensions 4 and 5 at the bottom of the furnace, though when these 'of al chamber,

`the top'ocf the furnace.

extensions are plugged up the hydrogen can be taken oif through the exhaust pipe 3 at What I cla-im asznew and desire to secure by Letters Patent of the United States, is,-.

. heated can be introduced in proximity to said tungsten heater.

2. In an electric furnace, the combination of a tubular tungsten heater, and means for maintaining a hydrogen atmosphere circulatin in and about said heater While materia to be heated. is being introduced therein.

3. In anelectric furnace, the combination of a chamber, means for supplying an inert gas thereto, and a tubular tungsten heater Within said chamber, said chamber having openings through which material to be heated can be introduced While the tungsten heater is atnormal running temperature.

4. In an electric furnace, the combination of a Chamberm,l plurality of tungsten heaters Within said chamber, means connecting said heaters .in series and spring-actuated means holding said connecting meansrin close Contact with said heaters.

5. In an electric furnace, a chamber having a sealed cover, heating members supported from said Vcover and connected in series,

and openings in said cover through v vhichv y Witnesses material to be heated can/be introduced Yinto said chamber or can be withdrawn therefrom. f-

6. rIn an electric furnace, the combination ofa chamber having a cover, a plurality of resistance Yheaters, supported fromsaid cover, a block -`electrically connecting said heaters,and a liquid cooled yoke connected said chamber supporting said yoke. y.

7. In an electric furnace, the combination of a chamber, a tungsten heater herein, current supplyterminals therefor, and means outside of Said chamber for adjusting the contact pressure between terminals yand heater.

8. In'an electric furnace,the combination with said block and a spring located outside of a chamber, a resistance heater ltherein,v

terminals for said heater and means actuvated by a spring located outside of said chamber for holding said terminals in con` tact With said heater irrespectiveV of its shrinkage.

9. In an electric furnace, the combination i of a chamber, a plurality of resistance heaters therein, a block electrically connecting said heaters, and a spring-supported yoke holding said block in contact with .said

heaters.

In witness whereof, I have hereunto set.4 `my hand this `9th day of October, 1908. AXEL APPELBERG.

.BENJAMIN B. HULL, HELEN Onronn. 

